Table of Contents
Introduction
Living organisms carry out the vital functions of control and coordination to respond to stimuli and maintain a stable internal environment. In chapter 7 of class 10 science, we look into how organisms sense their surrounding environments and respond to them through complex systems. This chapter focuses on the nervous system as well as endocrine system in animals and hormonal coordination in plants hence it has been able to bring out various ways that enable different parts of the body function together in order for an organism to survive. These are processes that can be very helpful if one wants to understand the dynamic interactions within biological systems responsible for sustaining life.
Both control and coordination are the key activities taking place in living organisms to keep the internal
environment stable and to ensure a proper response to certain signals.
These processes are conducted by the nervous system and the endocrine system.
Nervous System
The human nervous system regulates and integrates the activity of the body by use of electrical signals. It has two main parts namely; the central nervous system and the peripheral nervous system.
Central Nervous System (CNS)
Brain: Usually refers to within the body as the command center of bodily activities. They include the cerebrum, the cerebellum, and the brainstem among other sections.
Cerebrum: This is the part of the cerebral cortex in charge of planning and executing voluntary actions as well as thinking and memory.
Cerebellum: Stands, walks, and holds up the support of the body.
Brainstem: Is responsible for coordinating activities within the body that are not under volition such as the heart rate and the breathing system.
Spinal Cord: A neural connection to relay signals between or within the brain and the other organs/tissues of the body.
Peripheral Nervous System (PNS)
Relates CNS to the limbs and the organs.
Classification: Somatic nervous system- deals directly with the voluntary muscles while the Autonomic nervous system deals with involuntary muscles.
Neurons
Neurons have been described to be the fundamental components of the nervous system set.
BodyCell: It includes the nucleus and Cytoplasm The nucleus and cytoplasm are two of the principal organelles in a cell.
Dendrites: Accept signals and transport them to the main part of the cell.
Axon: Transports impulses away from the cell body.
Synapse: A small space between two neurons and here neurotransmitters assist in the transfer of impulses.
Reflex Action
An immediate reaction is made by an organism without giving much thought to the action being made.
Pathway: Stimulus → Receptor → Sensory Neuron → Spinal Cord → Motor Neuron → Effector → Response.
Human Brain
The human brain has three major parts: The human brain has three major parts:
Forebrain: This system houses the forebrain which is comprised of the cerebrum, thalamus, and hypothalamus.
Midbrain: Oversees the neurological functions including vision, hearing, movement, and coordination.
Hindbrain: Areflex is involved in four parts which are the small stem, cerebellum, pons, and medulla.
Coordination in Plants
Have none of the features of an animal but adapt to stimuli through what is referred to as growth movements.
Tropism: The action of changing position in a particular direction because of a stimulus from the outside world.
Phototropism: Response to light.
Geotropism: Response to gravity.
Hydrotropism: Response to water.
Chemotropism: Response to chemicals.
Nastic Movements: Retropasal actions to stimuli (e. g. touch in Mimosa pudica).
Endocrine System
It identifies a group of glands that release hormones into the bloodstream The part of endocrine system.
Hormones: Substances used for the communication of different processes and activity within the body.
Major Endocrine Glands
Pituitary Gland: known as the master gland of the other endocrine glands.
Thyroid Gland: Regulates metabolism.
Adrenal Glands: Aid in the secretion of adrenaline and cortisol, which are hormones used by the body in combating stress.
Pancreas: It involved in the regulation of blood sugar levels with the help of insulin and glucagon.
Gonads (Testes and Ovaries): Secretes sex hormones such as androgens, estrogen and progestogens.
Hormonal Coordination in Animals
This is basically the categories; growth and development, reproduction, metabolism and stress.
Example: Insulin regulates the blood sugar level due to its ability to promote the intake of glucose into cells.
Hormonal Coordination in Animals
Auxins: Releases the synthesis of nucleic acids and promotes elongation of cells and root formation.
Gibberellins: The following serves to encourage the growth of the stem, the germination of the seeds, and flowering.
Cytokinins: Encourage cell division and extend the life span of the leaves.
Abscisic Acid: Its function is to affect growth and to discourage dropping of seeds in other ways or putting them into dormancy.
Ethylene: They induce the ripening of fruits and the development of the abscession of leaves.
Control and Coordination Class 10 (Mcq Question and their Answer)
1. What is the main function of the nervous system?
a) Transport oxygen
b) Digestion
c) Control and coordination
d) Circulation
Answer: c) Control and coordination
2. The central nervous system consists of:
a) Brain and spinal cord
b) Brain and nerves
c) Heart and brain
d) Spinal cord and nerves
Answer: a) Brain and spinal cord
3. Which part of the brain controls voluntary actions?
a) Cerebellum
b) Medulla
c) Cerebrum
d) Hypothalamus
Answer: c) Cerebrum
4. The autonomic nervous system controls:
a) Voluntary actions
b) Involuntary actions
c) Reflex actions
d) Both voluntary and involuntary actions
Answer: b) Involuntary actions
5. What is a synapse?
a) Gap between two neurons
b) A type of hormone
c) A part of the brain
d) A type of neuron
Answer: a) Gap between two neurons
6. Reflex actions are controlled by:
a) Brain
b) Spinal cord
c) Heart
d) Lungs
Answer: b) Spinal cord
7. Which hormone regulates blood sugar levels?
a) Thyroxine
b) Adrenaline
c) Insulin
d) Testosterone
Answer: c) Insulin
8. The plant hormone that promotes cell elongation is:
a) Ethylene
b) Gibberellin
c) Auxin
d) Cytokinin
Answer: c) Auxin
9. The fight or flight hormone is:
a) Insulin
b) Adrenaline
c) Estrogen
d) Progesterone
Answer: b) Adrenaline
10. The cerebellum is responsible for:
a) Thinking and memory
b) Involuntary actions
c) Balance and coordination
d) Reflex actions
Ans c) Balance and coordination
12. Which of the following is a plant hormone?
a) Insulin
b) Adrenaline
c) Cytokinin
d) Thyroxine
Ans c) Cytokinin
13. Phototropism in plants is a response to:
a) Gravity
b) Light
c) Water
d) Touch
Ans b) Light
14. The part of the brain that regulates heartbeat and breathing is:
a) Cerebrum
b) Cerebellum
c) Medulla
d) Thalamus
Ans c) Medulla
15. The peripheral nervous system consists of:
a) Brain and spinal cord
b) Spinal cord and nerves
c) Nerves and brain
d) Nerves outside the brain and spinal cord
Ans d) Nerves outside the brain and spinal cord
16. Tropism is:
a) Non-directional movement
b) Growth movement in response to stimuli
c) Cell division
d) Hormone secretion
Ans b) Growth movement in response to stimuli
17. Geotropism in plants is a response to:
a) Light
b) Gravity
c) Water
d) Chemicals
Ans b) Gravity
18. Which part of the neuron receives impulses?
a) Axon
b) Synapse
c) Dendrites
d) Cell body
Ans c) Dendrites
19. The gland responsible for metabolism regulation is:
a) Pituitary gland
b) Thyroid gland
c) Adrenal gland
d) Pancreas
Ans b) Thyroid gland
20. What connects the brain to the rest of the body?
a) Cerebellum
b) Spinal cord
c) Medulla
d) Hypothalamus
Ans b) Spinal cord
21. The basic functional unit of the nervous system is:
a) Neuron
b) Hormone
c) Gland
d) Synapse
Ans a) Neuron
22. Hydrotropism in plants is a response to:
a) Light
b) Gravity
c) Water
d) Chemicals
Ans c) Water
23. The hormone that promotes fruit ripening is:
a) Auxin
b) Gibberellin
c) Ethylene
d) Abscisic acid
Ans c) Ethylene
24. Which part of the brain is involved in speech and language?
a) Cerebellum
b) Medulla
c) Cerebrum
d) Hypothalamus
Ans c) Cerebrum
25. The chemical messengers of the endocrine system are:
a) Neurons
b) Hormones
c) Neurotransmitters
d) Enzymes
Ans b) Hormones
26. Which gland produces insulin?
a) Pituitary gland
b) Adrenal gland
c) Thyroid gland
d) Pancreas
Ans d) Pancreas
27. Chemotropism in plants is responsible for :
a) Light
b) Gravity
c) Water
d) Chemicals
Ans d) Chemicals
28. The autonomic nervous system is divided into:
a) Central and peripheral systems
b) Somatic and autonomic systems
c) Sympathetic and parasympathetic systems
d) Sensory and motor systems
Ans c) Sympathetic and parasympathetic systems
29. The growth hormone in plants is:
a) Ethylene
b) Auxin
c) Abscisic acid
d) Gibberellin
Ans d) Gibberellin
30. Which of the following hormones is involved in stress response?
a) Thyroxine
b) Insulin
c) Adrenaline
d) Estrogen
Ans c) Adrenaline
31. Nastic movements in plants are:
a) Directional growth movements
b) Non-directional responses to stimuli
c) Growth responses to light
d) Responses to gravity
Ans b) Non-directional responses to stimuli
32. Which part of the neuron transmits impulses away from the cell body?
a) Axon
b) Dendrites
c) Synapse
d) Cell body
Ans a) Axon
33. The pituitary gland is located in the:
a) Neck
b) Brain
c) Abdomen
d) Chest
Ans b) Brain
34. Which hormone inhibits plant growth and promotes dormancy?
a) Auxin
b) Cytokinin
c) Abscisic acid
d) Gibberellin
Answer: c) Abscisic acid
35. The neurotransmitters are released at the:
a) Dendrites
b) Axon
c) Synapse
d) Cell body
Ans c) Synapse
36. Which part of the brain controls hunger and thirst:
a) Cerebrum
b) Cerebellum
c) Medulla
d) Hypothalamus
Ans d) Hypothalamus
37. Which of the following is not a part of the CNS?
a) Brain
b) Spinal cord
c) Nerves
d) Both a and b
Ans c) Nerves
38. The plant hormone that delays aging in leaves is:
a) Auxin
b) Cytokinin
c) Ethylene
d) Gibberellin
Ans b) Cytokinin
39. The part of the neuron that contains the nucleus is:
a) Dendrites
b) Axon
c) Cell body
d) Synapse
Ans c) Cell body